Pressure sensor with stress isolation platform hermetically sealed to protect sensor die

摘要

An electronic pressure sensor (10) is enhanced by attaching a sensor die (18) to a stress isolation platform (12) using an adhesive (42) having a similar thermal coefficient of expansion. The adhesive provides a hermetic seal between the stress isolation platform and the pressure sensor die. A via (20) in the stress isolation platform provides an opening for pressure to be applied to the sensor die. The stress isolation platform is attached to a plastic package body (16) via a semi- rigid adhesive (40) for providing stress isolation and a hermetic seal between the package body and the stress isolation platform. Any hostile chemical entering the via contacts an exposed diaphragm (50) of the sensor die to assert pressure against its piezoelectric network (52) to generate the electrical signals representative of the applied pressure but are kept away from the sensitive interconnects by the hermetic seals.